Effects of Ureteral Stent on Urologic Complications in Renal Transplant Recipients: A Retrospective Study

Abstract

The aim of the present study was to analyze the effects of ureteral stents used in renal transplantation on urologic as well as other complications. Cases of renal transplants from living or deceased donors performed in our hospital were retrospectively evaluated. The effects of the routine use of ureteral stents on postoperative complications were investigated. All outcomes and complications encountered during the postoperative follow-up were recorded. The Lich-Gregoire technique, which is a method of extravesical ureteroneocystostomy, was performed on all patients. One hundred and twenty-two patients underwent renal transplantation between 2001 and 2007 in our hospital. Stents were placed routinely in all patients. Leakage was observed in one patient, and one patient developed an obstruction; however, none of the patients developed an infection. A lymphocele developed in one patient. All urologic complications were treated without major morbidity. Graft loss did not occur. Complications following urinary anastomosis have a high rate of morbidity in renal transplantation. Ureteral stenting in renal transplant recipients prevents early urologic complications. The data generated in the current study were compared to the literature.

Keywords:

• ureteral stents
• urologic complications
• renal transplantation recipients
• other complications
• Lich-Gregoire ureteroneocystostomy

INTRODUCTION

Chronic dialysis prolongs the survival of patients with end stage renal failure; however, chronic dialysis does not improve the patient's quality of life or ensure rehabilitation. Technical advances in the surgical field, progress in immunology, and the introduction of new immunosuppressive agents into clinical practice have improved the success rates in renal transplantation considerably, with a marked reduction in mortality and morbidity rates. Surgical complications that occur during renal transplantation negatively affect graft survival and mortality rates. Early complications encountered during the early postoperative period remain a major problem. Most of the urologic problems necessitate early surgical revision. The rate of urologic complications ranges between 1 and 15%.^[1] The most common early complications include urinary leakage, and partial or total ureteral necrosis, whereas stenosis of the ureterovesical anastomosis and vesica-ureteral reflux are late complications.^[1–9]

Despite the use of the same surgical techniques in renal transplantation within the last 30 years, many centers have employed various techniques to minimize urologic complications. Ureteral stenting is one of these methods. Thus, in the present study, the effects of ureteral stenting on surgical technique in relation to urinary leakage and anastomotic stenosis, as well as the effects of ureteral stents used on the rate of complications, were examined.

MATERIALS AND METHODS

One hundred and twenty-two patients who consecutively underwent renal transplantation for the first time in the Transplantation Units of Etlik Ihtisas Hospital between 2001 and 2007 were included; 32 of the donors were from cadavers and 90 were from living-related donors (see Tables 1 and 2). The recorded pre-operative, intra-operative, and post-operative data on urinary tract anomalies and bladder pathologies were reviewed. In keeping with the study objectives, the patients were specifically evaluated for early urologic mechanical complications, such as urinary leakage, obstruction, infection, graft function, and response to the surgical method employed.

Table 1  Donor sources and study groups

Between 2001 and 2007	Number
Living donor	90
Deceased donor	32
Total	122

Table 2  Donor source

Donor source	Number
Mother	42
Father	22
Sibling	23
Cognate	—
Cadaver	32
Partner	3

The demographic features, immunosuppressive treatment protocols, acute rejections, chronic allograft nephropathies, and the rates of graft loss of the study patients are summarized in Table 3.

Table 3  The demographic features, protocols, and rejection rates of the study patients

	Stent (+)
Number of patients	122
Age (years)	17–68
Ratio of male-to-female gender	90/32
Age of donors (years)	15–67
Number of immunosuppression protocols
Tacrolimus + mikofenolate mofetil + corticosteroid	73
Cyclosporine + mikofenolate mofetil + corticosteroid	49
Acute rejection (N, %)	5 (4%)
Chronic rejection (N, %)	8 (6.5%)
Graft loss (N)	1

Immunosuppression and Antibiotics

Before and after surgery, all patients were administered antibiotics and immunosuppressants, as well as single doses of ceftizoxime pre-operatively. Prophylaxis with trimethoprim sulfamethoxazole for Pneumocystis carinii was continued for three months following surgery. Immunosuppression was provided by triple combination following the pre-operative induction treatment (tacrolimus or cyclosporine + mycophenolate mofetil, or azathioprine + corticosteroids).

Surgical Technique

The open nephrectomy method was used for all transplantations from living donors. In all recipients, ureteral anastomoses were performed using extravesical Lich-Gregoire ureteroneocystostomy method. The ureter length was measured and shortened so as to prevent kinking or stretching. Anastomosis of the ureter to the bladder mucosa was performed with 4-0 Vicryl, and the detrusor muscle was closed with 3-0 Vicryl by creating a submucosal tunnel. In all recipients, a truncated 4.8F double J ureteral stent (cut by approximately one-third) was placed into the bladder and renal pelvis. The same surgical technique was used for uretero-vesical anastomosis in the group in which routine stenting was not performed. To facilitate the anastomosis, an 8F straight catheter was used and removed after the anastomosis was completed. A negative-pressure silicon drain was placed into the iliac fossa of all patients, and was removed on average after 3–4 days (one day after the discharge resolved). In all patients, an 18F three-way catheter was placed. Foley catheters were removed after seven days in patients without urinary leakage, and the patients were closely monitored for voiding dysfunction. Ureteral stents were removed after approximately four weeks by cystoscopy under local anesthesia. Removal of the stents was performed under local anesthesia by daily treatment protocol, and ceftizoxime was administered before the intervention at a dose of 1g. The urologic and other surgical complications encountered are summarized in Table 4.

Table 4  Complications

Complications	Number (%)
Urinary leakage	1 (0.8)
Obstruction	1 (0.8)
Leakage + obstruction	—
Urinary stone	1
Urinary infection	—
Hematuria	—
Other complications
Lymphocele	2 (1.6)
Hematoma	—
Renal artery stenosis	1 (0.8)

Follow-up

Postoperative assessment for renal function and circulatory anastomoses were conducted on day 1 by ultrasonography and Doppler ultrasonography. Drains were frequently monitored for urinary leakage and obstruction. Fever associated with a urinary tract infection, bacterial growth in urine cultures >100,000 colonies/mL, and a decrease in serum creatinine levels to identify the risk of acute tubular necrosis were monitored daily. Patients were monitored for rejection, nephrotoxicity, and hepatotoxicity, and regular blood glucose measurements were obtained.

RESULTS

One hundred and twenty-two patients underwent renal transplantation with ureteral stenting between 2001 and 2007. Acute rejection developed in five patients, all of whom responded to pulse treatment. There was also no significant difference with respect to chronic allograft nephropathy.

Among all patients, the overall rate of urologic complications was 3.2%. Specifically, urinary leakage was observed in one patient with a ureteral stent. Obstruction occurred in one patient; however, no patients developed infections. A lymphocele was detected in one patient.

DISCUSSION

The current data in the literature on the advantages of routine stenting is controversial. Several retrospective analyses have reported a reduction of 0–7.7% in the frequency of urologic complications by the use of routine stenting.^[10–13] In the present study, the rate of urologic complications was 3.2%, which is compatible with the literature.

In addition to reduced graft-survival, urologic complications following renal transplantation may result in increased morbidity rates; thus, most urologic problems necessitate early surgical revision.^[1] The major causes of complications in renal transplantation are improper selection or surgical technique and insufficient evaluation of recipient/donor compatibility. The rate of complications ranges from 1–15%, depending on the presence of several factors, such as transplantation from a living or deceased donor, the presence of single or multiple arteries, a neurogenic bladder in the recipient, a lower urinary tract infection, or voiding dysfunction. These complications include ureteral obstruction, urinary leakage (i.e., pelvis, ureter, and bladder), and pelvic/ureteral necrosis.^[1–9] Most of these complications can be eliminated or reduced by the use of ureteral stenting.^[14,15]

In the study by Dominquez et al.,^[16] routine stenting was not recommended in renal transplant recipients bearing low urologic risks; however, its importance was emphasized in selected cases. In the study by Derek et al.,^[17] early urinary tract complications were reported to cause a significant increase in the frequency of acute renal failure. In a cost/benefit analysis, such complications were reported to cause significant economic burden due to the increased risk of morbidity.^[17] In the present study, it was also observed that the hospitalization period was significantly prolonged in relation to the encountered urologic complications. Due to obstruction, one of our patients was re-operated and hospitalized for an additional seven days. The cost of this hospitalization (1430 USD) was approximately 11 times higher than the cost of stenting (128 USD). Thus, it can be suggested that stenting is a beneficial procedure in terms of reducing cost, in addition to its effects on reducing the complications.

Benoit et al.,^[18] demonstrated a better improvement in renal function during the early postoperative period with the use of ureteral stenting. A significant reduction in perigraft fluid collection was detected in patients with ureteral stents.^[19] This is an important complication, which has a negative impact on graft survival if not corrected promptly.

The largest retrospective study was published by Sansolone et al.,^[20] in 2005. A total of 1004 transplant recipients were examined for early urologic complications. Significantly higher rates of urinary leakage and early stenosis occurred in patients without ureteral stents, whereas the use of ureteral stents was not associated with an increased rate of hematuria or urinary tract infections.

Double J ureteral stents, which play a role in the internal part of urologic procedures, provides safe, tolerable, and good urinary drainage between the kidney and bladder. These stents have some minor and major complications over the short- and long-term. The minor complications include hematuria, dysuria, frequency, suprapubic pain, and flank pain. The major complications are vesica-ureteral reflux, stent migration, incrustation, urinary infection, stent fragmentation, ureteral necrosis, and ureteral fistula formation. Most of these complications necessitate removal of the stent.^[21]

According to the outcomes obtained in this set of renal transplant patients, the use of ureteral stenting is associated with decreased rates of urologic complications. There was no difference between the groups with respect to urinary leakage, obstruction, and infection. The use of an external ureteroneocystostomy method has a significant impact on reducing the rates of these complications. In the last 50 years, many methods have been described, and the outcomes have been compared in relation to ureteroneocystostomy in renal transplantation.

Theoretically, placement of a stent for the development of an anastomosis is beneficial. The presence of a stent facilitates the development of an anastomosis and provides a wider lumen. A stent prevents kinking of the ureter and compression of the ureter by a perigraft fluid collection. It also circumvents redundant narrowing in the submucosal tunnel, hence decreasing the risk of obstruction. Urinary drainage is easily performed in grafts with higher rate of diuresis. Stents physically promote passage across the anastomosis and prevent urinary leakage from potential openings at the anastomotic site or small necrotic fields.^[17]

The most significant complications related to routine stenting are urinary tract infections. In a controlled study, the rate of urinary tract infections was reported to be 33% in patients with ureteral stents, whereas it was 5% in the group without stents.^[22] Surgical technique, treatment with broad spectrum antibiotics preoperatively and postoperatively, and careful clinical follow-up of the patients are important. The treatment costs of urologic complications when ureteral stents are not used outweigh the costs of complications caused by the use of ureteral stents. Double J stents are inexpensive and effective in the recovery process following renal transplantation, and thus they are commonly used depending on the preferences of the surgeon.

The disadvantage of stenting in renal transplantation is that it requires removal by cystoscopy. Cystoscopy is the most important part of the urologic procedure, and may cause serious complications. However, when the cases in the present study were examined, the lack of bacterial growth in urine cultures obtained before and after placement of the stent, as well as the lack of infection in spite of removal of the stent by cystoscopy introducing an additional risk of infection, were explained by the use of prophylaxis with broad spectrum antibiotics prior to intervention and the continuation of antibiotic prophylaxis for the first three months postoperatively. Ureteral stents, while preventing stenosis and urinary leakage, have been reported to increase the rates of infection.

In the study by Tavakoli et al.,^[22] ureteral stenting was performed in 112 cases, whereas ureteral stenting was not performed in 89 cases. They compared 231 renal transplant recipients and found significantly higher rates of ureteral obstruction and urinary leakage in patients without ureteral stents. In these series, the frequency of urinary tract infection was found to be increased in the group with ureteral stents. They reported that this finding was associated with the removal of the stent in a mean of 74.3 days and that the risk was lower when stents remained in situ <30 days. In the present study, the mean time for the removal of stents was 26.4 days. Thus, one of the most important causes for the lack of increase in the infection rate was the removal of the stent before four weeks.

In the randomized, prospective study conducted by Benoit et al.^[18] 97 transplantation patients with ureteral stents and 97 without stents were compared; the authors reported that the frequency of urinary tract infection was similar between these two groups, but the vesicoureteral leakage and obstruction significantly decreased in the patient group with ureteral stents. Based on these findings, Benoit et al.^[18] suggested the ureteral stenting. Furthermore, Samsolane et al.,^[20] based on amplification studies involving 1004 patients, emphasized the necessity of the routine use of stents in order to reduce the urological complications.

In addition to the use of ureteral stenting, the ureteroneocystostomy technique is also important in uretero-vesical anastomosis in terms of urinary leakage and strictures. The most commonly used Lich-Gregoire ureteroneocystostomy technique has been compared to many other methods, and various studies have reported that it is the best method with respect to hematuria, incrustation, urinary leakage, and strictures.^[23] In the present study, all patients were implanted with a stent and all underwent a Lich-Gregoire uretero-vesical anastomosis.

In conclusion, based on the results when we compared our results with the literature, it can be suggested that early urologic complications such as ureteral fistula, leakage, and stenosis in renal transplant patients were reduced through the use of ureteral stenting. Ureteral stenting did not increase the frequency of urinary tract infection. In the present study, the removal of the stents in a shorter period than four weeks will enhance the cost-effectiveness of this treatment modality, through diminishing these additional risks and decreasing the morbidity rates. In addition to the preference of the surgery team, double J stents should be performed primarily for cases of renal transplants from elderly or deceased donors or for cases with arterial injuries.

DECLARATION OF INTEREST

The authors report no conflicts of interest.